Before you specify
Frequently Asked Questions
Why does it take fewer sheets than the P-4 models?
Because a P-5 cutting head has far more cutting edges working on the same stack. The 51572 produces a particle of about 28 mm² against roughly 126 mm² for the P-4 51564 in the same cabinet, and that finer cut costs throughput — 14 sheets a pass at 20 lb bond against 22. This trade-off is universal across shredders, not a weakness of this model. If your policy allows P-4, you get substantially more throughput for the same money by choosing the 51564.
Is the 51572 NSA approved for classified material?
No. NSA/CSS Specification 02-01 requires a maximum particle of 1 mm x 5 mm and current listing on the NSA Evaluated Products List. The 51572 produces roughly 2 x 15 mm, which is DIN 66399 P-5 — a high commercial security level but not an NSA specification. No amount of P-5 rating substitutes for EPL listing. Use this machine for regulated commercial, medical, legal and financial destruction; for US classified material you need a purpose-listed high-security shredder.
What is the largest sheet it will take?
The throat is 16 inches wide, so anything up to that width feeds flat, including 11 x 17 tabloid, ledger stock, wide continuous-feed printouts and folded plan sheets. Length is not a constraint — a long sheet simply feeds through. Remember that the 14-sheet rating is quoted on 8.5 x 11 in paper, so wide stock should go in fewer sheets at a time. Two letter-size sheets can also be fed side by side, which speeds up bulk clearing.
How does the automatic oiler work, and what do I have to do?
The EvenFlow Lubricator meters oil slowly and continuously across the full width of the cutting cylinders while the machine is running, rather than depositing it in bursts. Your only responsibility is keeping the reservoir topped up with Dahle shredder oil — item 20721 in a 12 oz bottle, or 20722 by the gallon. Check it monthly under department use. Never substitute aerosol lubricant or cooking oil; both leave deposits that stiffen the cylinders and can void the cylinder warranty.
How often will the 45-gallon bin need emptying?
Less often than a P-4 machine of the same bin size, because P-5 shred is fine and settles densely. For a department feeding one machine from routine daily paperwork, weekly is a realistic expectation, with the bin-full sensor stopping the shredder before it overpacks. Bulk archive destruction is different — a day spent emptying banker's boxes will fill it. Bear in mind a full 45-gallon bag of P-5 shred is heavy, so change it before the cutout rather than after.
Does it destroy CDs, DVDs and credit cards?
Yes, and at the higher optical rating. The 51572 is O-4 for optical media alongside P-5 for paper, where the P-4 department models such as the 51564 and 51514 carry O-3. Dahle lists CDs, DVDs, credit cards, staples and paper clips among accepted materials. Feed discs individually rather than mixed into a stack of paper. Hard drives, USB sticks and anything with a metal enclosure are outside the rating and require a dedicated media destroyer.
Can it run continuously through a large backlog?
It uses a chain-driven continuous-duty motor with thermal protection, which is what allows sustained running rather than short cycles, and at 20 ft/min it is the fastest-moving machine in this batch. Dahle does not publish a specific run-time and cool-down figure for the model. If the thermal cutout does trip during heavy work, leave the machine switched on and idle so it can reset, and check that the bin is not full enough to be backing shred up into the cutting head.